The helminth-derived peptide GK-1 induces an anti-tumoral CD8 T cell response associated with downregulation of the PD-1/PD-L1 pathway.
Clin Immunol 2019;
212:108240. [PMID:
31299381 DOI:
10.1016/j.clim.2019.07.006]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 07/04/2019] [Accepted: 07/08/2019] [Indexed: 12/17/2022]
Abstract
CD8 T cells can kill malignant cells in an antigen-specific manner. However, anti-tumoral responses are usually limited by suppressive factors that curb the effector responses of tumor-infiltrating CD8 T cells. Therapeutic strategies to overcome intra-tumoral T cell suppression, for example immune checkpoint inhibition, have been clinically effective in patients with cancer. Here, we provide data that demonstrates that GK-1, a peptide derived from the parasite Taenia crassiceps, promotes an anti-melanoma CD8 T cell response with heightened effector characteristics that leads to an increased amount of tumor-infiltrating CD44+ IFN-γ-producing CD8 T cells. The response induced by GK-1 was associated with a reduction in the expression of PD-1 and PD-L1 on tumor-infiltrating CD8 and dendritic cells, respectively, effects that led to a dramatic decrease in tumor burden. Our results suggest that the immunomodulatory properties of GK-1 may promote a CD8 T cell response that may be therapeutically useful in the setting of cancer.
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